Casement window and door lock



Feb. 1, 1938. H. H. KISTNER CASEMENT WINDOW AND DOOR LOCK Filed April 23, 1935 Patented Feb. 1, 1938 UNITED STATES PATENT OFFICE Herman H. Kistner, Baltimore, Md., assignor to Kistner Lock & Appliance Company, a corporation of Maryland Application April 23, 1936, Serial No. 76,033

2 Claims.

-- actuated locking means for latch secured closure members.

Heretofore no satisfactory means has been available for dead locking window latches of the type commonly used, so as to prevent unlatching by breaking out a small piece of glass and reaching in from outside and turning the latch, and this invention aims to overcome this defect in a simple and secure way.

Another aim of the invention is to provide for clamping the window, door or other closure member tightly against its jamb to keep out cold air and dust, and to prevent rattling in the wind, and to lock the closure member against opening from either within or without except by use of the proper key.

Further aims and advantages of the invention appear in connection with the following description of the illustrative embodiments shown in the accompanying drawing, wherein Fig. l is a front view looking at the inner side of a portion of a double casement window provided with a common type of latch, showing my invention applied thereto;

Fig. 2 is a similar view of a portion of a single casement window showing another form of the invention;

Fig. 3 is a side view of the single type of lock shown in Fig. 2; and

Fig. 4 is a cross-section on the line 4-4 in Fig. 3 but showing the double type of lock as illustrated in Fig. 1.

The invention as illustrated is applicable to both wood and metal frame windows and doors having lever and cam type latches for clamping them tightly against the jamb, and comprises a key actuated multi-tumbler lock for preventing actuation of the latch when dead locked in closed position without interfering with the tightness of the clamping action.

The form of invention shown in Figs. 1 and 4 utilizes a well known type of multiple disc tumbler locking means, and that shown in Figs. 2 and 3 utilizes a well known pin tumbler locking means, but either type of locking means may be used as preferred, both being susceptible of being made in a large variety of combinations so that the likelihood of unauthorized persons possessing duplicate keys for any particular combination is remote.

Referring to the drawing, the window or door frame H is of any preferred construction, each of those shown being arranged to swing outwards, and is provided on its inner side with a pivoted latch I2, having a latch arm I3 adapted to be turned when the window or door is closed 5 to engage the keeper M, which has a wedge or cam surface l5 and is secured on the inner face of the center post !6 (Fig. 1) or side jamb ll (Fig. 2) of the window or door opening to clamp the door or window shut. 0

The latch is held against unlatching by means of a sliding bolt mounted in a casing I8 secured to the post or jamb by rivets or screws l9. The bolt is actuated by suitable rack and pinion mechanism under control of a key, and may be dead 15 locked in either of its two extreme positions. In the form shown in Figs. 1 and 4, the bolt 20 has a cross arm 2| on its end, the ends of the cross arm projecting beneath the adjacent ends of the latches l3 to prevent them from being turned down to disengage their keepers. This arm is secured on the shouldered end of the bolt by a pin 22 passing through both members, and the end of the bolt is spun over into a shallow groove countersunk in the arm surrounding the hole for the bolt, as shown in Fig. 4.

The sliding bolt 20 is provided with a rack 23 into which a pinion 24 engages, the pinion being formed on the end of the rotatable locking plug 25 which is mounted in the casing I8 and can be turned by a suitable key inserted in the key slot 26. The locking plug 25 is of the disc tumbler type, in which the tumblers and their springs are mounted in cross slots in the plug and normally project into an alining groove in the casing, as is well understood in the art. Such a locking plug cannot be rotated when dead locked, but by inserting the proper key it may be turned through an arc of making a half turn, or a complete turn of 360 may be made, thereby throwing the bolt half way or its full stroke, as may be needed to withdraw the outer end of the bolt from blocking the path of movement of the latch. The key may be withdrawn in either position and the locking plug thus locked against 45 turning, thereby dead locking the bolt in either position.

In the form of invention shown in Figs. 2 and 3, the casing 21 is secured to the jamb member I1 directly in line with the keeper I4 so that the 50 bolt 28, when locked in projected position, will stop the unlatching of the latch member as in the form shown in Figs. 1 and 4. The actuating and locking means comprises a pinion 29 carried by a rotatable locking plug 30 of the pin and 55 tumbler type, in which the tumblers 3| are arranged in holes drilled for them in the inside of the casing and the driving pins 32 are carried in alining holes in the locking plug and are engaged by the nibs of the proper key to lift the tumblers against the pressure of their springs 33, thereby permitting turning of the plug, as is well understood.

Inboth forms of the invention the locking plugs and are retained in their casings by detents that cannot be removed without removing the casings from the post IE or jamb I! as the case may be, as is well understood in the art. Furthermore, at least one of the rivets or screws which secure the casings in place is covered by the bolt in its projected locking position so as to prevent removal of the casing without unlocking the bolt. Thus my improved construction makes it extremely difllcult to remove any part of the lock or casing by any means available for use from the outside.

The invention is applicable to existing latch installations without cutting into the window frame or removing the original latch, and is easy to install and simple to operate as the position of the bolt may be determined by observation.

The invention is not restricted to the details of construction shown in the drawing.

I claim:

1. A locking device for pivoted latch members of the type adapted to swinging windows and doors comprising an axially movable locking bar and a rotatable operating means therefor disposed in a casing mounted upon the latch enaging post or jamb of the door or window adjacent to the latch keeper, means for permanently securing said casing to the post or jamb, and key responsive means for holding said rotatable member against rotation, said locking bar covering said securing means in its latch locking position to prevent removal of said casing.

2. A locking device for a latch type swinging window or'door fastening mounted on the window or door and having a cam element mounted on the jamb with which the latch member is adapted to engage to clamp the window or door in closed position, said locking device comprising a casing mounted on the jamb adjacent to said cam element and having a sliding member adapted to be projected into the path of movement of said latch member to prevent its disengagementrfrom said cam element, means carried by said casing for locking said sliding member in projected position, and means for securing said casing to said,

jamb, said securing means being inaccessible in projected position of said sliding member where-. by said locking. device cannot be removed when said locking means is in locking position.

HERMAN H. KIS'I'NER. 

